# File lib/em-http/mock.rb, line 74
    def self.parse_register_args(args, &proc)
      args << proc{|client| proc.call(client); ''} if proc
      headers, data = case args.size
      when 3
        args[2].is_a?(Hash) ?
          [args[2][:headers], args[2][:data]] :
          [{}, args[2]]
      when 4
        [args[2], args[3]]
      else
        raise
      end

      url = args[0]
      method = args[1]
      [headers, url, method, data]
    end